The installation and use of the telephone is very common nowadays, and the telephone is really convenient and practical. The mouthpiece of the telephone, however, when placed at the relative position while being used, is usually polluted by the user's saliva. For the reason that viruses carried therein can multiply easily for a long time, the mouthpiece can produce a damp smell or other bad smell and make others nauseated. Especially, it is easy to infect other disorders and very dangerous if the telephone is used by a man who has pulmonary disorders. Therefore, the telephones of some offices are fixedly provided with a sterilizing piece outside of every mouthpiece for preventing the multiplication of viruses. The sterilizing piece is really sanitary and it is not easy to smell the dampness of the telephone. Besides, owing to the function of fragrance compounds therein, the user can smell a slight fragrance. The sterilizing piece is really progressional. Sterilizing piece, however, can only be kept a short time limit, changing of the sterilizing piece is required at least every two weeks. Although there are some firms which provide the service of changing the sterilizing piece for the companies in the business district of a city and the firms always charge a relatively cheap service charge, there are some places which do not have such benefits. The house of the residential area located far from urban areas has only a telephone or two, and the aforesaid service benefit may not be available to such a house. That is always the problem for the household.